Field of the Invention
The present invention relates generally to a process for preparing a dry or semi-dry sausage product. In one aspect, the present invention relates to the preparation of sliced dry sausage, wherein the sausage is heat treated with casings or moulds and the dehydrating step is performed using conditioned air and microwaves.
Description of the Related Art
Different processes have been used to manufacture cured, smoked, dried, and semi-dried sausages, including processes for preparing dry sausage (e.g., pepperoni, Genoa salami). In these processes, the initial meat mixture is cured and thereafter dried or heated in air, sunlight, drying rooms, or smokehouses. See FAO Corporate Document Repository (2010) “Meat Drying”. The cure and drying process may last for days, or even weeks. A wide variety of final products and inconsistent qualities results from the use of well-established recipes and techniques.
Dry sausage is typically prepared by stuffing the desired meat mixture into fibrous casings and curing the resultant product for extended periods (e.g., over 7 days). This particular sausage is most commonly served in thin slices, with or without the casing (the casing being removed after heat treating). Sliced dry sausage are used in a variety of food applications, such as toppings, sandwiches, salad bars, and are often used in making pizzas (e.g., pepperoni pizzas).
The typical current practice is to prepare the dry sausage using conventional processes employing blending, stuffing the meat mixture into casings, heat treating or cooking a meat mixture, and curing, following which the product is thinly sliced. The slices may then be used by consumers or by foodservice operators (e.g., toppings, sandwiches, salad bars, and pizzas). Because the drying and curing process requires from several days to several weeks, production capacity for a manufacturing facility is limited to the amount of space allocated to the drying process. This process is capital intensive, and requires a tremendous amount of product to be held in process at any given period of time. Again, the preparation process of dry sausage (e.g., pepperoni) may take days or weeks. Several patents describe methods for to curing or drying dry sausage products.
U.S. Pat. No. 2,346,232 describes the preparation of semi-dried meat for food ration purposes by exposing the meat mixture to a turbulent air flow to reduce the moisture content from an original range of 45 to 85% to a range of 20 to 55%. The air used in this process was at a temperature of 0° C. to 30° C. (32° F. to 86° F.) and the air is moved across the meat surface at a velocity of 1 to 18 feet/second. The meat products discussed in U.S. Pat. No. 2,346,232 are produced in ¼ to 1¼ inch thick layers or in ropes of ⅜-inch diameter for drying. For ⅜-inch ropes, drying reduces the moisture to 28% in 8 to 13 hours, while the 1¼-inch layers require 13 days. The benefits of turbulent flow are alleged to be increased by 40% early in the process where the air contacts a moist surface, however, the effect of the turbulent air flow of this patent is substantially reduced as the drying continues. For example, in one test reported in U.S. Pat. No. 2,346,232, drying of ⅜-inch ropes from 55% to 40% moisture took just three hours, while a further reduction to 28% required an additional five hours. U.S. Pat. No. 2,346,232 does not disclose any direct relationship between the humidity of the air used in the process and the time of drying. Further, the product is held in flat trays in the examples.
Another process for preparing sausages is disclosed in U.S. Pat. No. 3,482,996 where the meat compositions include dehydrated, spun, edible protein fibers or dehydrated fibrous products derived from spun, edible protein fibers. The fibers allegedly take up the moisture which is removed in a drying room. U.S. Pat. No. 3,482,996, however, does not disclose the use of an air flow to dry sausage products.
U.S. Pat. No. 4,265,918 describes a technique that includes immersion of a meat product in a curing solution, followed by vacuum dehydration. The initial hydration step is to about 105 to 125% of the product's original weight, followed by vacuum treatment to reduce the overall product weight to 70 to 95% of its original weight. U.S. Pat. No. 4,265,918 does not disclose the use of air flow to dry sausage products.
Yet another process is described in U.S. Pat. No. 4,279,935 where bactericides and bacteriostats are first added to a meat, followed by treatment with an acidic mixture to reduce the pH to about 5.7. The sausage is then heated to 58° F. and dried to reduce the average moisture level to 35%. U.S. Pat. No. 4,279,935 discloses a drying time of 5 to 20 days and does not disclose the use of air flow to dry sausage products.
Further a process described in WO 2005/092109 uses vacuum-drying methods for drying meat products. However, this publication does not contemplate the use of air flow to dry sausage products; in fact, it uses low air pressure.
Additionally, these current processes require the dry sausage to be held in its casing during the curing and drying phase, thereby reducing the rate at which moisture may be removed from the product and adding to manufacturing cost. Holding the dry sausage in its casing during drying also disallows the ability to slice the product prior to drying, which would increase the surface area of the product and aid in moisture removal.
Accordingly, there exists a need for a method of manufacturing dry sausage that may address or even overcome one or more of the foregoing disadvantages. Further, there exists a need for improving the quality and the manufacturing processes of dry sausages.